<?php
function h($str){
    return htmlspecialchars($str,ENT_QUOTES,'UTF-8');
}
$files = scandir(__DIR__);
echo '<ul>';
foreach($files as $file){
    if ($file[0]=='.'){
        continue;
    }
    if ($file==='index.php'){
        continue;
    }
    $hfile = h($file);
    echo '<li><a href="'.$hfile.'">'.$hfile.'</a></li>';
}
echo '</ul>';